Population centers, mission personnel, and equipment may be endangered if flight vehicles fly off-course. To address this, many flight vehicles are equipped with flight safety systems that terminate flight when these vehicles fly off-course. The flight safety systems, however, can be costly in terms of flight hardware, personnel, and range assets for tracking and communicating with the flight vehicles. Furthermore, recent expansion of vehicle flight envelopes may exacerbate the issue of tracking a particular vehicle when it has the capability of flying on its own over large areas. Providing sufficient numbers of range assets along the flight path has become challenging, if not prohibitive from cost and availability standpoints.
Although autonomous flight safety systems may be used, the volume of flight hardware associated with such systems can be prohibitive from a weight, packaging, and cost standpoint. Furthermore, accommodating anomalous navigation failures is a challenge for autonomous flight safety systems. For example, in order for an autonomous flight safety system to operate and terminate a flight of a vehicle if the vehicle is flying off-course, the position of the vehicle needs to be known. Identifying the position of the vehicle is the function of a navigation system of the vehicle. However, when the navigation system is not functioning properly (e.g., is anomalous), the vehicle's position cannot be measured. Sensors off-board the vehicle may be employed to mitigate this risk, but these sensors can add complexity and cost.
Further, when the navigation system is not functioning properly, autonomous flight safety systems may terminate a flight prior to reaching an intended target. Terminating the flight prior to reaching the intended target jeopardizes mission success because mission objectives are typically configured to execute only at the intended target.